TY - JOUR
T1 - Leaf-litter breakdown in tropical streams
T2 - Is variability the norm?
AU - Boyero, Luz
AU - Pearson, Richard G.
AU - Gessner, Mark O.
AU - Dudgeon, David
AU - Ramírez, Alonso
AU - Yule, Catherine M.
AU - Callisto, Marcos
AU - Pringle, Catherine M.
AU - Encalada, Andrea C.
AU - Arunachalam, Muthukumarasamy
AU - Mathooko, Jude
AU - Helson, Julie E.
AU - Rincón, José
AU - Bruder, Andreas
AU - Cornejo, Aydeé
AU - Flecker, Alexander S.
AU - Mathuriau, Catherine
AU - M'Erimba, Charles
AU - Gonçalves, José F.
AU - Moretti, Marcelo
AU - Jinggut, Tajang
N1 - Publisher Copyright:
© 2015 by The Society for Freshwater Science.
PY - 2015/6
Y1 - 2015/6
N2 - Many forested headwater streams are heterotrophic ecosystems in which allochthonous inputs of plant litter are a major source of energy. Leaves of riparian vegetation entering the stream are broken down by a combination of biotic and abiotic processes and, in most temperate and boreal streams, provide food and habitat for dense populations of detritivorous invertebrates. However, tropical streams in different parts of the world show substantial variability in the number and diversity of leaf-shredding detritivores (hereafter detritivores). We used data obtained with standardized methods from multiple streams in Africa, the Americas, Asia, and Australia to test the hypothesis that this variability would lead to differences in the relative role of detritivores and microorganisms in the breakdown process.We also tested the hypotheses that variability in litter breakdown rates changes with litter type (native litter mixtures vs nonnative alder [Alnus glutinosa]) and is higher across regions within than outside the tropics. We found that litter breakdown rates were highly variable across sites, with no consistent pattern within geographic areas, although litter consumption by detritivores was negligible at several sites, all in America. Geographic patterns of litter breakdown also varied between litter types, with higher breakdown rates for alder than for native litter in most but not all regions.When litter breakdown rates at the tropical sites were compared to previously reported values from temperate and boreal regions, we found that differences in variability between tropical and temperate sites were inconsistent, with great differences among studies. Further global-scale studies will be needed to assess the extent to which latitudinal changes in the diversity and composition of microbial and detritivore assemblages contribute to variability in litter breakdown rates.
AB - Many forested headwater streams are heterotrophic ecosystems in which allochthonous inputs of plant litter are a major source of energy. Leaves of riparian vegetation entering the stream are broken down by a combination of biotic and abiotic processes and, in most temperate and boreal streams, provide food and habitat for dense populations of detritivorous invertebrates. However, tropical streams in different parts of the world show substantial variability in the number and diversity of leaf-shredding detritivores (hereafter detritivores). We used data obtained with standardized methods from multiple streams in Africa, the Americas, Asia, and Australia to test the hypothesis that this variability would lead to differences in the relative role of detritivores and microorganisms in the breakdown process.We also tested the hypotheses that variability in litter breakdown rates changes with litter type (native litter mixtures vs nonnative alder [Alnus glutinosa]) and is higher across regions within than outside the tropics. We found that litter breakdown rates were highly variable across sites, with no consistent pattern within geographic areas, although litter consumption by detritivores was negligible at several sites, all in America. Geographic patterns of litter breakdown also varied between litter types, with higher breakdown rates for alder than for native litter in most but not all regions.When litter breakdown rates at the tropical sites were compared to previously reported values from temperate and boreal regions, we found that differences in variability between tropical and temperate sites were inconsistent, with great differences among studies. Further global-scale studies will be needed to assess the extent to which latitudinal changes in the diversity and composition of microbial and detritivore assemblages contribute to variability in litter breakdown rates.
KW - Decomposition
KW - Microorganisms
KW - Shredders
KW - Tropical streams
KW - Variability
UR - http://www.scopus.com/inward/record.url?scp=84949093664&partnerID=8YFLogxK
U2 - 10.1086/681093
DO - 10.1086/681093
M3 - Artículo
AN - SCOPUS:84949093664
SN - 2161-9549
VL - 34
SP - 759
EP - 769
JO - Freshwater Science
JF - Freshwater Science
IS - 2
ER -